Mine
by coffeebuddha
Summary: A visit from Ethan leaves Derek feeling rather jealous. Reid/Morgan established relationship.


It wasn't that Derek didn't like Ethan. He _did_ like him, which made things so much worse than if the other man had turned out to be a complete ass. He was, Derek had mused to himself several times over the last few days since Ethan'd come into town, a quintessential Nice Guy. He was clever, quick with a joke, and even quicker to pick up the check. His entire attitude toward life seemed very laid back and live-and-let-live-esque. And when he'd found out about Derek and Spencer's relationship, he hadn't even blinked, just grinned widely and pounded Spencer on the back and told Derek to 'try to get the kid to loosen up before he snaps and goes all mad scientist on our asses'.

Any of those things by themselves would have been enough to make Derek feel amicable toward him under normal circumstances. And there was no reason to suspect that these weren't normal circumstances, except...

Except for the way that Ethan's eyes seemed to linger just a little too long on Spencer when he didn't think anyone would notice. Or the fact that he seemed to jump at any chance to touch the other man. And the way he kept bringing up inside jokes and immediately turning to shoot Derek an apologetic look and say 'Long story; you had to be there.' was making his blood pressure rise more than was strictly healthy.

The last night he was in town, Spencer invited him to come over to the house for dinner. By the time the meal had ended, Derek's fingers were stiff and sore from how tightly he'd been gripping his fork and his jaw ached from grinding his teeth. When Spencer waved him into the kitchen to clean up the dishes, Derek had watched the other two men disappear into the living room to 'talk' with narrowed eyes. Their pans had never been cleaner than they were when he was done scouring them.

It was after midnight when Ethan finally said something about having an early flight back to New Orleans in the morning. Derek forced a tight smile and joined Spencer in saying goodbye-"Such a _shame_ that you couldn't stay longer." "We'll have to do this again." "Give us a call when you get in so we know you got there safely."-and even showed great restraint by not physically throwing him out the door when his goodbye hug with Spencer lasted longer than was really necessary.

After they'd closed the door behind Ethan, Spencer turned to Derek with a small smile, which faltered a bit when he saw the stormy glint in Derek's eyes. He opened his mouth to say something, but before he could, Derek had him backed up against the wall, his lips captured in a rough, unyielding kiss. He made a muffled, surprised noise that made Derek growl and thrust his tongue in his mouth, claiming it with hard, possessive caresses. Spencer clung to Derek, his arms tight around his neck, and when his knees wobbled, Derek pressed his body against the younger man's to hold him up.

Derek pulled back after several minutes and Spencer turned bright, dazed eyes on him, his lush mouth red and swollen from abuse. Derek stared at those lips and said lowly, "Bedroom. _Now_."

Spencer's tongue darted out to wet his lips and he nodded. His breathing was harsh and ragged, but he managed an enthusiastic 'Yes, sir' before slipping out from between the wall and Derek's body to hurry down the hallway, dropping clothes as he went.

* * *

Spencer arched under Derek's hands, his arms tight and straining against the cuffs that tethered him to the headboard, his body desperately rising to chase Derek's teasing, constantly retreating lips. He whimpered and thrust his hips up when Derek ducked his head down so that his breath ghosted over his hard, leaking cock. "Derek," he pleaded, his voice already hoarse. "Derek, please."

Derek smiled cooly and lightly raked his fingernails down his lover's sides, delighting in the shivers that shook his slim form. "Please what? What do you want from me, Spencer?"

Spencer moaned and hooked his leg around Derek's torso, desperately trying to pull him down for more-_any_-contact. "Know what I want," he said petulantly, his fingers curling into fists as Derek moved up to flick his nipples with his tongue. "Derek," he whined, his voice getting high on the second syllable when one of Derek's legs shifted and rubbed against his dick.

"Yeah, but I want to hear you say it," Derek said. He kissed and licked a trail up from Spencer's nipple to suck a mark high on his neck. High enough that his shirts wouldn't cover it. The kind of mark everyone would see. Derek examined it with satisfaction as Spencer writhed underneath him.

"Fuck me," he begged, dropping his head back so that Derek had better access to his neck. "Just please fucking _fuck me_ already. "

Derek leaned back and hooked an arm under Spencer's knee, positioning himself at his slick, stretched entrance. Spencer watched him with dark, half lidded eyes, and Derek reached up to brush the backs of his fingers over the damp, flushed curve of his cheek as he pushed all the way in with one hard, smooth thrust. Spencer's eyes fluttered closed and his mouth went slack as he moaned and pushed back against Derek, urging the older man to move faster, harder.

Derek's fingers slid back into Spencer's hair and he fisted a handful, pulling on it hard enough to make Spencer hiss. Derek set a ruthless, punishing pace that had Spencer whimpering and pleading and moving senselessly underneath him. He press his face into the curve of Spencer's neck, biting and sucking more marks, murmuring a barely coherent stream of 'mine, not anyone else's, belong to me, belong with me, _mine_' that had Spencer nodding and gasping out 'yes, yours, God yes, _take me_' until they were both too breathless to say anything at all.

* * *

Spencer stretched lazily next to Derek and draped an arm over his waist. "So," he said as he cuddled closer. "What exactly brought that on?"

Derek frowned against Spencer's hair and shifted so that they fit together more comfortably. "I know Ethan's one of your oldest friends, but didn't the way he was acting strike you as a little strange?"

Spencer propped his chin up on Derek's chest so that he could look at him. "How do you mean?"

Derek shrugged and lightly stroked his fingers up and down Spencer's spine. "He was just a little...touchy feely with you. And I don't like some of the looks he was giving you."

Spencer pushed up onto his elbow and gaped at Derek like he couldn't figure out if he was serious. After a few seconds he started laughing-actually _laughing_-in Derek's face. "Derek, he has a girlfriend! Didn't you hear him talking about Melissa? They've been together for years!"

Derek blinked up at Spencer and felt his face and ears start to burn with embarrassment, because, now that Spencer mentioned it, the name did sound familiar...

* * *

**Thank you for reading! Feedback is overwhelmingly appreciated.**

This was originally written for a kinkmeme over on LJ. The prompt was "Jealous!Morgan is one of my favourites. Especially if he's jealous of Ethan..."

Nothing belongs to me.


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